1. Tarenaya hassleriana (Chodat) H. H. Iltis, Novon. 17: 450. 2007.
Cleome hassleriana Chodat, Bull. Herb. Boissier 6(app. 1): 12. 1898
Plants (50-)100-200 cm. Stems sparsely branched; glandular-pubescent. Leaves: stipular spines 1-3 mm; petiole 2.5-7.5 cm, glandular-pubescent, with scattered spines 1-3 mm; leaflets 5 or 7, blade elliptic to oblanceolate, 2-6(-12) × 1-3 cm, margins serrulate-denticulate, apex acute, surfaces glandular-pubescent abaxially, glandular adaxially. Racemes 5-30 cm (10-80 cm in fruit); bracts unifoliate, ovate, 10-25 mm. Pedicels 20-45 mm, glandular-pubescent. Flowers: sepals (reflexed after anthesis), green, linear-lanceolate, 5-7 × 0.8-1.3 mm, glabrous; petals usually pink or purple, sometimes white (or fading to white by second day), oblong to ovate, 20-30(-45) × 8-12 mm; stamens purple, 30-50 mm; anthers 9-10 mm; gynophore 45-80 mm in fruit; ovary 6-10 mm, glabrous; style 0.1 mm. Capsules (25-)40-80 × 2.5-4 mm, glabrous (in straight alignment with gynophore and pedicel). Seeds 10-20, 1.9-2.1 × 1.9-2.1 mm, tuberculate. 2n = 20.
Flowering late spring-late summer. Disturbed roadsides, vacant lots, waste areas, gravel pits, lakeshores, streambeds; 0-200(-800) m; introduced; Que.; Ala., Ark., Conn., D.C., Fla., Ga., Ill., Ind., Iowa, Ky., La., Md., Mass., Mich., Miss., Mo., Nebr., N.J., N.Y., N.C., Ohio, Okla., Pa., R.I., S.C., Tenn., Tex., Va., W.Va., Wis.; South America; introduced also in Mexico, West Indies, Central America.
Tarenaya hassleriana is native to Argentina, Brazil, and Paraguay. It is often cultivated and has sometimes escaped and naturalized. In cultivation and various floras, it has long been treated under the name Cleome spinosa; that name properly applies to the next species.